Fix qt qhash seed for QT >= 5.6.0

Author: marioba

tests/src/core/testqgsogcutils.cpp

@@ -33,8 +33,13 @@ class TestQgsOgcUtils : public QObject
     void initTestCase()
     {
       // Needed on Qt 5 so that the serialization of XML is consistent among all executions
+#if QT_VERSION < QT_VERSION_CHECK( 5, 6 ,0)
       extern Q_CORE_EXPORT QBasicAtomicInt qt_qhash_seed;
       qt_qhash_seed.store( 0 );
+#else
+      qSetGlobalQHashSeed( 0 );
+#endif
+
 
       //
       // Runs once before any tests are run